Fibre Channel (FC) is standardized as typical communication standards that are used for Storage Area Network (SAN) where storage devices and computers such as servers are connected. In addition, Fibre Channel over Ethernet (FCoE) standards are also known, where FC frames are encapsulated in Ethernet frames and then transmitted.
According to the FC standards, a device such as a server logs in with an FC fabric before communicating with a device existing in the FC fabric. On the other hand, the FCoE standards introduce the “FCoE Initialization Protocol (FIP)” to provide a service for a node on an Ethernet to log in with an FC fabric. Preparation for a login using the FIP is made as follows. An ENode which is a node on an Ethernet searches for an FCoE switch by using Ethernet multicast. The FCoE switch sends the Media Access Control (MAC) address of the own device by unicast to the ENode in response to the multicast packet from the ENode. The ENode connects with the FCoE switch by using the MAC address received from the FCoE switch, and then logs in with the FC fabric connected to the FCoE switch.
One example for controlling access to a storage device in a storage system is that information on higher-level apparatuses which are permitted to access the storage device is previously registered in a control apparatus controlling the storage device, and the control device, when receiving an access from a higher-level apparatus, compares information identifying the higher-level apparatus extracted from a received access command with the previously registered information. Another example is that an accessing apparatus which is to access a storage device sends an authentication identifier encrypted using a key associated with the request source of the access, and then a control apparatus, when receiving the access, determines based on the authentication identifier received from the accessing apparatus whether to permit the access to data stored in the storage device.
On the other hand, one example for controlling a transmission path in a storage system is that, when a switching node which has stored therein bandwidth control parameters receives an access request for accessing a storage device, establishes a path of optimal bandwidth on a relay network by using bandwidth control parameters appropriate for the request. Another example is that each router adds the identification information of the own device to path vector Type-Length-Value (TLV) information which propagates through a network, and transfers the resultant to an adjacent router, so that each router detects paths from the path vector TLV information, and if a node fails in the network, determines an optimal path from the paths detected from the path vector TLV information.
Please refer to Japanese Laid-open Patent Publications Nos. 2004-362600, 2002-529804, 2004-56728, and 2007-67690.
The above login process using the FIP is performed under a precondition that an ENode communicates with a single FCoE switch. Therefore, if the ENode is connected to a plurality of FCoE switches, the ENode has difficulty in determining which FCoE switch to connect with for the login process.